This invention relates to a system for remotely monitoring and controlling elevator operating conditions. More particularly it relates, to an elevator monitor and control system in which the system has a battery back-up so that the final stop position of the elevator car may be detected even upon power failure.
Positional control of an elevator system is generally achieved by digital position control in which the elevator car position is detected by counting pulses generated as the car travels along a hoistway. While the display of the elevator car position in the car or on the landing floor may be turned off upon power failure without any serious problem, it is necessary that the car position be displayed on a monitor panel even during a power failure. Also, when a power failure takes place while the elevator car is travelling, the displayed car position often differs from the actual stop position because of the idle run of the elevator car after the completion of the display process.
Japanese Patent Laid-Open No. 53-73756 discloses a battery back-up system in which the display is updated until the elevator car comes to a complete stop after the occurrence of a power failure. Also, Japanese Patent Laid-Open No. 1-256477 discloses a system in which exchanging of an elevator operating data between a elevator control apparatus and a monitoring panel is achieved by a series transmission system. In this system, a display data processing function is added in one part of transmission control and is backed up by a battery.
In displaying the car position in a conventional elevator monitor and control system, a battery back-up is necessary for each elevator control apparatus, and a car position display data transmission signal line between the elevator control apparatus and the monitor panel is necessary for each elevator control apparatus, making the elevator monitor and control system expensive.